The invention relates to network management and in particular, to methods and apparatus for the management of routes and paths in telecommunications networks.
In today""s large telecommunications networks such as core networks used for Internet service providers (IMPS) or major corporate backbones, network management plays an important role in maintaining network stability, performance and efficiency. Network management is used to perform a variety of functions including the detection and correction of fault conditions, the identification, configuration and monitoring of use of network devices for cost allocation and performance evaluation.
Presently, the vast majority of networks are manager at the physical or device level by a centralized management entity commonly referred to as a network manager server (hereinafter xe2x80x9cnetwork managerxe2x80x9d) whereby devices in the network such as routers and physical layer interfaces are each individually polled by the network manager for status updates. However, in many situations, this process is not time-efficient.
For example, in the event of a congestion point causing unusual traffic delays or a failures causing a traffic interruption along a particular routing path, each network device located along that particular path and involved in the transmission of the traffic delayed or interrupted as a result of the congestion point or failure must be polled by the network manager to locate the source of the problem. Polling multiple devices each time a problem arises along a particular routing path is therefore time-consuming and as a result, substantially lengthens the time necessary to solve the problem.
Because polling of multiple network devices is time-consuming, most problems encountered in a network may deteriorate or improve by the time a network manager is able to track down the root of the problem, making it more difficult to ascertain its true nature. Moreover, in many cases, clients only report network problems long after their occurrence which, by that time, may not be visible problems anymore. This is particularly true of congestion points which are intermittent by their very nature and only occur in heavy traffic conditions.
In ascertaining the nature of a particular problem, it is often necessary for the network manager to determine which clients are affected and the manner in which these clients are affected. This typically requires a network-level analysis of each problem by considering the performance history of the particular routes and paths used by each client. A route is a static concept typically defined by a source endpoint and a destination endpoint in a network. By contract, a path is a dynamic concept associated with a particular route. A path is defined as the set of network devices and their respective interfaces traversed by traffic travelling in a particular direction at any given point in time on the particular route.
However, current device-level management applications do not provide the necessary tools for efficiently monitoring routes and paths. As a result, these problems become virtually impossible to solve and may persist indefinitely. Therefore, there is a need to provide network operators with the ability to monitor the performance history of routes and paths for efficient troubleshooting of problems arising in a network.
Another drawback of the use of device-level management is that it does not address real-time performance issues at a routing path level which often arise in a network as a result of problems occurring at the device level such as congestion points and link or equipment failures. Device-level management only deals with performance issues for which the network devices are individually responsible. However, this xe2x80x9cdevice-level viewxe2x80x9d does not provide a path-level understanding of the overall real-time performance of all the devices defining a particular path of a particular route.
For example, in correcting a congestion problem, device-level management does not address whether the data transmitted on a particular source-destination route follows the intended path which may have been specifically provisioned for it or whether it has been rerouted to an alternate path.
When traffic is rerouted due to a failure in the network, another real-time performance issue not addressed by device-level management is whether the alternate path chosen has the requisite capacity for accommodating the traffic delayed or interrupted or whether the traffic as redirected will maintain the same level of service it had prior to being redirected. As network routes are currently sold to network clients with a specific quality of service (QoS), adequate configuration and path provisioning of network routes is becoming increasingly important. Therefore, there is a need for providing a network with adequate real-time performance monitoring and path provisioning capability for maintaining performance in a network and meeting ever increasing QoS demands.
The need to deal with device-level problems in a more time-efficient manner and address real-time performance issues arising as a result of the occurrence of device-level problems has triggered the emergence of what is now known in network management as trace routing. Trace routing applications allow some form of network-level management of paths and routes by relying on test messages to perform path discovery of specified routes. In particular, current trace routing implementations determine the path likely to be followed by traffic for a particular source-destination route by sending one or more test packets from the source node to the destination node and summarizing the results. However, this method has a number of disadvantages. First, the trace routing of any given source-destination route can only be performed from the source node. Another disadvantage is that most network devices are not properly instrumented to do this function and do not treat the test packets with the same priority than normal traffic, Therefore, the results obtained with this method are not truly representative of how the network devices handle their respective traffic in real-time. As a result, there is a need for an improved network management system for managing and monitoring paths and routes in a network and also for monitoring the behaviour of network devices in real-time.
It is an object of the invention to obviate or mitigate one or more of the above identified disadvantages and shortcomings of current network management applications.
The invention provides a cost-effective and efficient new route and path management (RPM) framework for network management of telecommunications networks by monitoring the network-level concepts of routes and paths. By monitoring paths and routes in a network, the RPM system provides network managers with the added capability of troubleshooting, performance monitoring, service level planning and provisioning paths between any source-destination endpoints (routes) in a network. In a preferred embodiment, the RPM system is incorporated in an Internet protocol (IP) network and is designed to be operable in a simple network management protocol (SNMP) environment. The RPM system is comprised of a data collector for collecting routing data from the individual network devices, a management server for processing the routing data collected into manageable route and path objects for tracing and performance monitoring, a database for storing the results and a graphical unit interface (GUI) for allowing a user to trace routes and paths in the IP network and monitor routing performance.
By comparison with device-level management applications, the present invention advantageously allows the real-time determination of permissible paths having the requisite capability for the transmission of data on a given set of routes and routing protocols.
Yet another advantage of the present invention compared to device-level management techniques is that it provides means for storing and providing, on demand, route history and path-level multi-metric performance history for future provisioning and troubleshooting of the routes and paths monitored.
Similarly to current device-level management applications, the invention allows real-time monitoring and reporting of device-level performance. Yet still another advantage of the present invention over device-level management is that it also provides path-level real-time and historical performance of routes and paths monitored.
Yet still another advantage of the present invention over device-level management techniques is that it provides means for raising or clearing quality of service (QoS) alarms against routes and paths monitored.
In another preferred embodiment, the RPM system as described above also has a management information base (MIB) in which the route and path objects managed by the management server are made available to other network entities and applications via SNMP.
Yet still another advantage of the present invention is that by using an MIB for SNMP storage of the route and path objects managed, the tracing and routing performance results generated by the management server may be remotely accessed by any SNMP entity.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.